Efficient unconditionally secure signatures using universal hashing

Abstract

Digital signatures are one of the most important cryptographic primitives. In this work we construct an information-theoretically secure signature scheme which, unlike prior schemes, enjoys a number of advantageous properties such as short signature length and high generation efficiency, to name two. In particular, we extend symmetric-key message authentication codes (MACs) based on universal hashing to make them transferable, a property absent from traditional MAC schemes. Our main results are summarised as follows. We construct an unconditionally secure signature scheme which, unlike prior schemes, does not rely on a trusted third party or anonymous channels.We prove information-theoretic security of our scheme against forging, repudiation, and non-transferability.We compare our scheme with existing both “classical” (not employing quantum mechanics) and quantum unconditionally secure signature schemes. The comparison shows that our new scheme, despite requiring fewer resources, is much more efficient than all previous schemes.Finally, although our scheme does not rely on trusted third parties, we discuss this, showing that having a trusted third party makes our scheme even more attractive.